The FlashFender DF Deluxe from Topeak are a set of ultra-light polypropylene rear fenders that fit under the saddle. The Duo Fixer holder (included) allows you to use the space under the saddle so that you can combine 2 different accessories: a black fender with an upper holder and a transparent fender with a lower holder, essentially allowing you to attach the black fender above saddle mounted accessories with the supplied bracket or below saddle mounted accessories with the supplied bracket.Material: Polypropylene / Engineering grade polymer Compatibility: Upper - TubiMaster GX DF, NanoMaster DF, TailLux DF lights, and FlashFender DF with upper bracket Lower - Topeak QuickClick saddle bags or most strap type saddle bags, FreePack and FlashFender DF with lower bracket Attachment: Duo Fixer on saddle rail Size: 29 x 8.5 x 2.15 cm / 11.4 x 3.3 x 0.84 (Upper) 29 x 8.5 x 1.8 cm / 11.4 x 3.3 x 0.71 (Lower) Weight: 26 g / 0.92 oz (Upper), 22 g / 0.78 oz (Lower)